Leetcode Add Binary

https://leetcode.com/problems/add-binary/

Author: skysign

Leetcode Add Binary/main.py

@@ -0,0 +1,33 @@
+class Solution:
+    def addBinary(self, a: str, b: str) -> str:
+        l_max = max(len(a), len(b))
+        l = l_max - min(len(a), len(b))
+        if len(a) < len(b):
+            a = '0' * l + a
+        if len(b) < len(a):
+            b = '0' * l + b
+
+        carry = 0
+        answer = ['0' for _ in range(l_max)]
+
+        for idx in range(-1, -l_max - 1, -1):
+            v = int(a[idx]) + int(b[idx]) + carry
+            if v == 3:
+                carry = 1
+                answer[idx] = str(1)[0]
+            elif v == 2:
+                carry = 1
+                answer[idx] = str(0)[0]
+            elif v == 1:
+                carry = 0
+                answer[idx] = str(1)[0]
+            elif v == 0:
+                carry = 0
+                answer[idx] = str(0)[0]
+
+        answer = ''.join(answer)
+
+        if carry == 1:
+            answer = '1' + answer
+
+        return answer

Leetcode Add Binary/test_main.py

@@ -0,0 +1,11 @@
+from unittest import TestCase
+from main import Solution
+
+class TestSolution(TestCase):
+    def test_add_binary(self):
+        sln = Solution()
+        self.assertEqual(sln.addBinary('11', '1'), '100')
+
+    def test_add_binary2(self):
+        sln = Solution()
+        self.assertEqual(sln.addBinary('1010', '1011'), '10101')